Variegation

Variegation, in plants, is a condition in which other colours are exhibited in parts where the normal colour should be green. Thus white, yellow, or other tints take the place of green in the leaves and other herbaceous parts. Yet variegation is regarded in botany as a disease, the causes of which are unknown. All that is yet determined respecting it is that it is invariably accompanied by a more or less complete suppression of the chlorophyll, the green granular matter which underlies the cuticle of the green parts of plants. Although often presenting similar peculiarities to chlorosis, another plant-disease, the cause of which is equally obscure, variegation is distinguished from it by the presence of chlorophyll in larger or smaller patches in the leaves, branches, or stems of the affected subjects. Variegation is usually a permanent characteristic, or may be made so by careful methods of propagation, and is compatible with vigorous health. These considerations give an importance to variegated plants in ornamental gardening which they would not otherwise possess. Variegated pelargoniums and many other bedding plants, perennial herbs and annuals, and some shrubs and trees derive their popularity as ornaments of the flower-garden from their variegation, which in many cases is so brilliant that it is substituted for flowers in the production of colour effects. Variegation is rarely perpetuated by seed; when it appears in a plant it can only be increased by means of cuttings, layers, division, or budding and grafting. In rare instances some tendency is shown in variegated plants to revert to the normal state; this is especially so in those that are grafted or budded. Inversely also the scion is found to exert influence upon the stock occasionally. Reversion to the original state is usually prevented by pruning away the first indications of it.